A “burst” as referred to herein is a data sequence of limited length. Although this term is most familiar in the field of optical networks, the term as used herein also includes short data sequences for transmission from a source to a destination in, e.g., a time-division multiplexed wireless network or a wireline packetized network.
Optical burst-mode transmission has been proposed as a way to increase the efficiency with which wavelength channels are used in all-optical WDM networks. For example, U.S. patent application Ser. No. 10/411,039, “Optical Network Wit Subwavelength Grooming,” cited above, describes a WDM ring network, and U.S. patent application Ser, No. 10/426,388, “System and Method for WDM Communication with Interleaving of Optical Signals for Efficient Wavelength Utilization,” also cited above, describes a WDM mesh network, both suitable for burst-mode transmission.
One important feature of the networks described in the above-cited patent applications is that passive wavelength-selective components can be used to assure that the receiver at each destination receives only those bursts that lie in a wavelength channel dedicated to that destination. On the other hand, an originating node can generally send out bursts in any of various wavelength channels, each corresponding to a particular intended destination.
In such a network, as well as in wireless and wireline networks posing analogous problems, it is desirable to schedule the bursts so that bursts from different origins do not collide; i.e., so that they do not arrive concurrently at a common destination. When propagation delays between origin and destination node pairs are insignificant, well-known algorithms can be used to generate schedules that reliably make efficient use of the available wavelength channels and timeslots.
However, the problem becomes much more difficult when delays must be taken into account. Until now, there has lacked an efficient scheduling algorithm that takes into account the various propagation delays between node pairs.